/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2018 by Blender Foundation.
 * All rights reserved.
 *
 * Contributor(s): Sergey Sharybin.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file BKE_subdiv_foreach.h
 *  \ingroup bke
 *  \since September 2018
 *  \author Sergey Sharybin
 */

#ifndef __BKE_SUBDIV_FOREACH_H__
#define __BKE_SUBDIV_FOREACH_H__

#include "BLI_sys_types.h"

struct Mesh;
struct Subdiv;
struct SubdivForeachContext;
struct SubdivToMeshSettings;

typedef bool (*SubdivForeachTopologyInformationCb)(
        const struct SubdivForeachContext *context,
        const int num_vertices,
        const int num_edges,
        const int num_loops,
        const int num_polygons);

typedef void (*SubdivForeachVertexFromCornerCb)(
        const struct SubdivForeachContext *context,
        void *tls,
        const int ptex_face_index,
        const float u, const float v,
        const int coarse_vertex_index,
        const int coarse_poly_index,
        const int coarse_corner,
        const int subdiv_vertex_index);

typedef void (*SubdivForeachVertexFromEdgeCb)(
        const struct SubdivForeachContext *context,
        void *tls,
        const int ptex_face_index,
        const float u, const float v,
        const int coarse_edge_index,
        const int coarse_poly_index,
        const int coarse_corner,
        const int subdiv_vertex_index);

typedef void (*SubdivForeachVertexInnerCb)(
        const struct SubdivForeachContext *context,
        void *tls,
        const int ptex_face_index,
        const float u, const float v,
        const int coarse_poly_index,
        const int coarse_corner,
        const int subdiv_vertex_index);

typedef void (*SubdivForeachEdgeCb)(
        const struct SubdivForeachContext *context,
        void *tls,
        const int coarse_edge_index,
        const int subdiv_edge_index,
        const int subdiv_v1, const int subdiv_v2);

typedef void (*SubdivForeachLoopCb)(
        const struct SubdivForeachContext *context,
        void *tls,
        const int ptex_face_index,
        const float u, const float v,
        const int coarse_loop_index,
        const int coarse_poly_index,
        const int coarse_corner,
        const int subdiv_loop_index,
        const int subdiv_vertex_index, const int subdiv_edge_index);

typedef void (*SubdivForeachPolygonCb)(
        const struct SubdivForeachContext *context,
        void *tls,
        const int coarse_poly_index,
        const int subdiv_poly_index,
        const int start_loop_index, const int num_loops);

typedef void (*SubdivForeachLooseCb)(
        const struct SubdivForeachContext *context,
        void *tls,
        const int coarse_vertex_index,
        const int subdiv_vertex_index);

typedef void (*SubdivForeachVertexOfLooseEdgeCb)(
        const struct SubdivForeachContext *context,
        void *tls,
        const int coarse_edge_index,
        const float u,
        const int subdiv_vertex_index);

typedef struct SubdivForeachContext {
	/* Is called when topology information becomes available.
	 * Is only called once.
	 *
	 * NOTE: If this callback returns false, the foreach loop is aborted.
	 */
	SubdivForeachTopologyInformationCb topology_info;
	/* These callbacks are called from every ptex which shares "emitting"
	 * vertex or edge.
	 */
	SubdivForeachVertexFromCornerCb vertex_every_corner;
	SubdivForeachVertexFromEdgeCb vertex_every_edge;
	/* Those callbacks are run once per subdivision vertex, ptex is undefined
	 * as in it will be whatever first ptex face happened to be tarversed in
	 * the multi-threaded environment ahd which shares "emitting" vertex or
	 * edge.
	 */
	SubdivForeachVertexFromCornerCb vertex_corner;
	SubdivForeachVertexFromEdgeCb vertex_edge;
	/* Called exactly once, always corresponds to a single ptex face. */
	SubdivForeachVertexInnerCb vertex_inner;
	/* Called once for each loose vertex. One loose coarse vertexcorresponds
	 * to a single subdivision vertex.
	 */
	SubdivForeachLooseCb vertex_loose;
	/* Called once per vertex created for loose edge. */
	SubdivForeachVertexOfLooseEdgeCb vertex_of_loose_edge;
	/* NOTE: If subdivided edge does not come from coarse edge, ORIGINDEX_NONE
	 * will be passed as coarse_edge_index.
	 */
	SubdivForeachEdgeCb edge;
	/* NOTE: If subdivided loop does not come from coarse loop, ORIGINDEX_NONE
	 * will be passed as coarse_loop_index.
	 */
	SubdivForeachLoopCb loop;
	SubdivForeachPolygonCb poly;

	/* User-defined pointer, to allow callbacks know something about context the
	 * traversal is happening for,
	 */
	void *user_data;

	/* Initial value of TLS data. */
	void *user_data_tls;
	/* Size of TLS data. */
	size_t user_data_tls_size;
	/* Function to free TLS storage. */
	void (*user_data_tls_free)(void *tls);
} SubdivForeachContext;

/* Invokes callbacks in the order and with values which corresponds to creation
 * of final subdivided mesh.
 *
 * Returns truth if the whole topology was traversed, without any early exits.
 *
 * TODO(sergey): Need to either get rid of subdiv or of coarse_mesh.
 * The main point here is th be abel to get base level topology, which can be
 * done with either of those. Having both of them is kind of redundant.
 */
bool BKE_subdiv_foreach_subdiv_geometry(
        struct Subdiv *subdiv,
        const struct SubdivForeachContext *context,
        const struct SubdivToMeshSettings *mesh_settings,
        const struct Mesh *coarse_mesh);

#endif  /* __BKE_SUBDIV_FOREACH_H__ */
